The Shadow Door (elsewhere Chronicles) [Paperback]

It's bad enough when Max, Rebecca, Noah, and Theo just think Grandpa Gabe's house is haunted. But then the old movie projector in the library opens a passageway to a world of monsters and creatures made of shadows - a place of secrets and dangers set loose when the sun sets. The only weapons to fight them lie in the land on the other side of the Shadow Door. . .